Bug 20821 – Cache property transitions to speed up object initialization

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Maciej Stachowiak]

EarlyBoyer spends 16.6% of its time in cti_op_put_by_id_generic, much of it under StructureID::addPropertyTransition. A lot of this time could be removed by inline caching property transitions - the old structure ID, the new structureID, and the offset to write to (and a call to resize if needed). DeltaBlue is also somewhat affected (3.6% in put_by_id_generic) as is Raytrace, though in the case of RayTrace much of the badness could just be due to Arguments not being very clever.

See bug 20813.

[Maciej Stachowiak]

Created attachment 23389 [details]
patch mostly by oliver with some bug fixes by me (needs ChangeLog, cleanup)

[Oliver Hunt]

Created attachment 23406 [details]
Fully implemented transition cache, now with a bonus feature: correctness

[Oliver Hunt]

Comment on attachment 23406 [details]
Fully implemented transition cache, now with a bonus feature: correctness

Removing review flag, this apparently breaks gmail :-(

[Oliver Hunt]

Comment on attachment 23406 [details]
Fully implemented transition cache, now with a bonus feature: correctness

Cameron lied to me, it works fine!

[Cameron Zwarich (cpst)]

Comment on attachment 23406 [details]
Fully implemented transition cache, now with a bonus feature: correctness

I think "failuresCases" would probably be better as "failureCases".

You have some extra blank lines, like CTI.cpp:1900 and Machine.cpp:2474.

Perhaps sIDC would be better as structureIDChain or chain? What do you think?

Other than that, r=me.

[Oliver Hunt]

	M	JavaScriptCore/ChangeLog
	M	JavaScriptCore/VM/CTI.cpp
	M	JavaScriptCore/VM/CTI.h
	M	JavaScriptCore/VM/CodeBlock.cpp
	M	JavaScriptCore/VM/CodeGenerator.cpp
	M	JavaScriptCore/VM/Machine.cpp
	M	JavaScriptCore/VM/Machine.h
	M	JavaScriptCore/VM/Opcode.h
	M	JavaScriptCore/kjs/JSObject.h
	M	JavaScriptCore/kjs/PutPropertySlot.h
	M	JavaScriptCore/kjs/StructureID.cpp
	M	JavaScriptCore/kjs/StructureID.h
	M	JavaScriptCore/masm/X86Assembler.h
Committed r36401